Abstract
Glutamate receptors represent a potential target for neuroprotection in neurodegenerative neurological conditions. Perampanel, a non-competitive α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor (AMPAR) antagonist, is clinically approved for the management of epilepsy. Perampanel's neuroprotective effects have been reported in global and focal cerebral ischemia models, but the cellular mechanisms remain incompletely understood. Therefore, we studied the potential neuroprotective effects of perampanel in rats using the pial vessel disruption (PVD) stroke model, an established focal cortical non-reperfusion ischemic stroke model. Perampanel was given once intraperitoneally (3 mg/kg body weight) 1 h after PVD surgery and repeated on days 2-3 post-surgery. On the fourth day post PVD, animal behavioral assays and imaging, biochemical, and electrophysiological analyses were performed. Compared to vehicle control, perampanel in PVD-treated rats significantly inhibited hippocampal neurodegeneration and long-term potentiation deficits. Perampanel also attenuated PVD-induced motor deficits, depressive/anxiety-like behaviors, and hippocampal-dependent cognitive impairment. In addition, perampanel prevented the PVD-induced downregulation of surface-expressed GluA1 and GluA2 AMPARs and increased phosphorylation of GluA1 at S831 and S845. Molecular docking analysis revealed perampanel binding to transmembrane regions M1, M3 and M4 of GluA1 and GluA2 subunits. Together, our results show that perampanel attenuated PVD-induced neurodegeneration and behavioral deficits by blocking AMPARs and decreasing GluA1 and GluA2 internalization. In addition, this study shows the neuroprotective potential of perampanel through the inhibition of neuroinflammation mediated by activated microglia and astrocytes following cerebral ischemia. This study is the first to evaluate perampanel in the pial vessel disruption model of ischemia without reperfusion, a clinically relevant stroke paradigm that differs fundamentally from middle cerebral carotid artery occlusion and photothrombosis stroke models.